18x28x1 Exact MERV 12 Plus Carbon AC Furnace Filters 6 Pack Trimmers Two separate set points can

Two separate set points can be adjusted from 4 to 7 pH and 900 to 1800 ppm (mg/L)

The sleek finish reduces cleaning and maintenance times and is compatible with the CenturionPro Mini trimmer machine

and propagating smaller cuttings

• Dimensions: 18

Helps grow healthy plants

18x28x1 Exact MERV 12 Plus Carbon AC Furnace Filters 6 Pack Trimmers Two separate set points canNordic Pure Custom MERV 12 Plus Carbon air filters are made based on the actual measurements so be sure to measure your current filter to get the EXACT dimensions before ordering. As with all Nordic Pure filters, the effective life of your filter depends on the environment in which you live. We recommend changing 1 and 2 filters every 30 90 days. Our 4, 5 and 6 inch thick filters could last up to 6 months. EXACT MEASUREMENT: Furnace and air condition